The sending and receiving of short messages has, to date, been offered as a telecommunications service in GSM radio networks, wherein subscriber A can transfer up to 160 alphanumeric characters in one transmission session to subscriber B (cf.: Funkschau 19/98, pages 67 to 69). Efforts currently are being made to implement this service in fixed networks as well, e.g., in the Public Switched Telecommunications Network (PSTN) or the Integrated Services Digital Network (ISDN). A publication on the subject of “Access and Terminal (AT)—Short Message Service (SMS) for PSTN/ISDN” has been produced at the European Standardizations Institute for Telecommunications ETSI under registration number DES/AT-030009 Vol. 0.1.1; 2001-02. This SMS service in the fixed network enables short messages to be sent and received in the fixed network with appropriate fixed-network telephones (both ISDN telephones and PSTN telephones). In this service, messages are always sent and received via a service center specially designed for this purpose, called the Short Message Service Center (SMSC), which is connected to the public telephone network.
For the parallel operation of several SMS-compatible terminals on an analog or digital fixed-network connection, a numeric identifier known as the terminal identifier (TID) is currently used to address a short message to a required terminal. The user is able to assign such a TID specifically to a terminal. The terminal in question then responds only to calls from the Short Message Service Center that correspond precisely to this one TID. However, it does not permit short messages to be addressed to SMS-compatible extensions, known as SMS entities (extensions for receiving short messages) of cord-connected or cordless fixed-network terminals that are configured as a private branch exchange and can be operated in parallel on the fixed network; e.g., DECT portable units of a DECT cordless telephone or internal subscribers of telecommunications systems.
In ISDN private branch exchanges operated on the ISDN network, it is known for the individual extensions of the telecommunications system to be addressed via multiple subscriber numbers (MSN).
An object of the present invention, therefore, is to address short messages in a fixed network, both to fixed-network terminals that are operated as standalone units in the fixed network or to terminals that are operated in parallel in the fixed network and to SMS-compatible extensions known as SMS entities (extensions for receiving short messages), of cord-connected or cordless fixed-network terminals that are configured as private branch exchanges and operated either as standalone units or in parallel in the fixed network.